single-fibered - Single Fiber Convenience Methods

Quick Start

To use single-fibered in an existing SBT project with Scala 2.11 or a later version, add the following dependencies to your build.sbt depending on your needs:

libraryDependencies ++= Seq(
  "io.chrisdavenport" %% "single-fibered" % "<version>"
)

Cancelation

Callers of a single-fibered action share one running computation, but they do not share a cancelation fate. The computation runs on its own fiber, so canceling any individual caller detaches only that caller: the computation keeps running and the remaining callers still receive its result.

The tradeoff is that the computation runs to completion even once every caller has walked away. For a deduplicated read - a cache fill, a token refresh, a downstream fetch - that is usually what you want, since the work would have happened anyway and the next caller gets a warm result. If your action is expensive enough that you would rather abandon it when nobody is waiting, guard it with a timeout inside the action itself rather than relying on caller cancelation.

Prior to 0.3.1, cancelation was shared: canceling whichever caller happened to arrive first aborted the computation and failed every other caller with a CancellationException. Callers that never canceled could be failed by one that did.